Grab



May '25 1926.

D. J. BARNARD GRAB Filed Nov. 1L, 1924 2 Sheets-Sheet l Patented Mey 25, 1926.

E@ i ST 'E S' earanr eiseres-'g DUDLNY JAMES BARNARD, or BARNING, ENGLAND.

GRAB.

Application" Ie.l November 4, 1924. Serial' No. 747,851.

In the specication to a prior patent (No. 1,477,530) granted to me, a form of mechanism isdescribed comprising a vertically disposedgravity catch pivoted to one ofcthe top bar plates `said'catcli being adapted4 toeiigage with a toothed memberl provid'edfoii thesheave block'plate on the same side', the lower end'ot'tlie gravity catch being arranged to coact withth'e locking latch.v

It hasb'een `found in'practice that when, as frequently happens when handling material`or1 largesize, the bucket sections are prevented from closing, the vertically dis! posed' gravity catch binds on the toothed member and prevents-the separation of the two parte ivhenthe grab is dumped.

It is: proposed to overcome this diflie'ulty according to the present invention by mounting the vertically disposed gravity catch on that partofthe grablocated at the head thereoifadapted to engage the carriage ofthe transporterf'or like deviceandv to vprovide a pin or liker part on the sheave block plate or onaipart carried thereby said 'pin being solocated in relation to the hook on the gravity catch that said part-s only come into operation while the grab is being supported byv the transporten carriage but fall free from each other when the on thehauling chain.

In the aceompanying` drawingswliich illustrate. one embodiment' of f this invention Figure 1 isa side elevation showing the operative parts oi the grab in the position they occupy when the grab is closed and supported by the liaulingichain.

Figures 2 and 3 are views in side and front elevation respectively on an enlarged scale illustrating details ofz the locking mechanism; and, n

Figure l isa similar view to Figure 2 grab is supported showing the position of the locking mechamsm when the grab is closediand supported bythe transporter carriage.-

In the drawings 1* and 2 are the bucket sections pivoted on independentpins 3-aiid 4 on a crossbeam 5. 6 and 7 are the top cross bars and 8 the spreader arms, one being-arranged at each corner of thek bucket The means for maintaining the sections. normal balance ofthe operative parts ofthe grab consist cip-*two vertically disposed telescopic devices arranged one on each side of the sheave blocks, one vmember 9 'of each de-` vice being secured to the cross-beam 5' the other member 1() being arranged to slide'.

thereon and in a bracket- 11y secured to the lower slieave bloekplate 12 springs v13 being provided to take up the shock when the partV comes to the limits of itsfmovements.

The locking mechanism which forms the sub-ject oi'the present invention comprises a gravity rcatclilpivoted at 14 to the plate 12 of the lower sheave block, said gravity catchY comprising a hooked member 15 adapted to coact and engage with a pin 16 carriedfby the cross-beam 5, a horizontally disposed weighted member 17 and an' upwardly eX- tending` memberf18 provided at its upperl end witha pin19 adapted to coact with andA to `*be engaged'by a hooked memberv 20 pivoted on one oifthe legs of a vertically'. disposed member 21 the upper endof which constitutes the member adapted to -be engaged by the carriage provided on the transporter or the like device and carries the entire load during-the lperiod of transportation.

The member 21, as more clearly shown iii Figure 3 is forked at its lower end, the legs of said member being arranged to straddle the plates 22 'oi the upper slieave block each of said legs lbeingarranged to slide between guides 23.

For the purpose of maintaining the hooked member 15 oi the gravity catch in itsy operativefposition a pin or `projection 24 is provided on the inner face ofi-the weighted member 17 adapted to be engaged by aplate- 25 carried'by a vertically disposed rod 26V the rod 26 is arranged to coact with a part 28 secured to the plate 22 of the upper sheave block.

In operation, assuming the grab to be supported by the hauling chain 31 as shown in Figures 2 and 3, the free end of such chain being secured to a lixed part of the grab, for example, to the stud 32 provided on the block plate 22, the weight of the grab is supported by the hooked member 15 engaging with the pin 16 and if the grab is dumped and the chain 31 slackened the weighted member 17 will cause the hook to disengage itself automatically from said pin and fall clear of the hook 20. On the chain 31 being hauled in and the grab raised the bucket sect-ions will fall apart. This automatic disengagement on dumping is permitted by rea-son of the tact that the load is removed from the hook 15 and that the plate 25 is. as shown in Figure 3, out of engagement with the pin 24. Immediately the lower sheave block is lowered away from theupper sheave block the rod 26 is forced upwardly by the spring 29 so as to bring the plate 25 against the pin 24. and when the hook 15 is again lowered into contact with the pin 16 the plate 25 and rod 26 are depressed against t-he action ot' the spring 29 and the hook is then drawn under the pin 16 and is maintained in this position by the plate 25.

When it is desired to transport the grab to another position the transporter carriage is caused to engage with the member 21, and the hauling chain 31 is slackened thereby causing the grab to fall slightly into the position shown in Figure a so as to bring the hook 20 into engagement with the pin 19 on the member 1S and the enlarged parts 30 on the lower ends of the legs of the member 21 into engagement with the lower ends ot' the guides 23, the entire weight oit the grab being now taken by the transporter carriage through the member 21. By this means the hooked member 15 of the gravity catch is maintained in its locken position. Immediately the member 21 is released from the transporter carriage and the load is supported by the chain the member 21 drops into its lowest position and frees the hook 2O from the pin 19.

I claim 1.'In a grab of the type described provided With means connecting the cross-beam carrying the bucket sections and movable sheave block, the combination ot means comprising a pin on the cross-beam, a gravity catch pivoted on the lower sheave block, guide members on the side plates of the upper sheavc block, means slidably mounted in said guide members adapted to coact with the travelling carriage ot a transporter, a vertically disposed hook shaped member pivoted on said means adapted to coact with the gravity catch and to hold said catch in engagement with the pin on the cross-beam when the grab is supported by the transporter carriage.

2. In a grab of the type described provided with means connecting the cross-beam carrying the bucket sections and movable sheave block, the combination of means comprising a pin on the cross-beam, a gravity catch pivoted on the lower sheave block, guide members on the side plates oi the upper sheave block, means mounted in said guide members adapted to coact with the travelling carriage of a transporter, a hook shaped member pivoted on said means adapted to coact with the gravity catch and to hold said catch in engagement with the pin on the cross-beam when the grab is supported by the transporter carriage, and spring controlled means on the movable sheave block adapted to coact with and control the position ot' the gravity catch.

3. In a grab ot the type described provided with means connecting the cross-beam carrying the bucket sections and movable sheave block, the combination of means comprising a pin on the cross-beam, a gravity catch comprising a vertically disposed hook shaped member, a horizontally disposed weighted member and a vertically disposed pin carrying member pivoted on the lower sheave block, guide members on the sidel plates ot' the upper sheave block` means slidably mounted in said guide members adapted to coact with the travelling` carriage ot' a transporter, and a vertically disposed hook shaped member pivoted on said means adapted to coact with the pin carrying member ot the gravity catch and to hold the hook shaped member ot' the gravity catch in engagement with the pin on the cross-beam when the grab is supported by the tran,"- porter carriage.

4. In a grab of the type described provided with means connecting the cross-beam carrying the bucket sections and movable sheavc block, the combination ot means comprising a pin on the cross-beam, a gravity catch comprising a vertically disposed hook shaped member, a horizontally disposed weighted member and a vertically disposed pin carrying member pivoted on the lower sheave block, guide members on the side plates of the upper sheave block, means slidably mounted in said guide members adapted to coact with the traveling carriage of a transporter, a vertically disposed hook shaped member pivoted on said means adapted to coact with the pin carryingmen'iber oi" the gravity catch and to hold tbe hook-shaped member ot the gravity catch in engagement with the pin on the crossbeam when the grab is supported by the transimrter carriage. and spring controlled means on the movable sheave block adapted tocoact with; the'weighted: member of; the grzwitycatchgto controhthe position or: said gravity catch.

flnfa: grab 1of the single chaintype providedavithmeans connecting the cross-beam carrying the bucket; sections and. movable sheave block, the combination otmeans come prising a pin` onth-e `cross-beam, a? gravitycatch pivoted onthe lower sheave block, guide members on the side plates of the upper sheave block, means adapted to coact with the travelling carriage o't' a transporter comprising a member provided with two legs slidably mounted in said guide members, means on the lower ends of said legs adapted to limit the sliding movement of said member, and a vertically disposed hook shaped member pivoted on one of the legs ot' said member adapted to coact with the gravity catch and to hold said catch in engagement with the pin on the cross-beam when the grab is supported by the transporter carriage.

6. In a grab of the type described provided wit-h means connecting the cross-beam carrying the bucket sections and movable sheave block, the combination of means comprising a. pin on the cross-beam, a gravity catch pivoted on the lower sheave block, guide members on the side plates of the upper sheave block, means adapted to coact with the travelling carriage of a transporter comprising a Jfork-shaped member 'adapted to straddle the plates of the upper sheave block and slidably mounted in said guide members enlargements on the ends of the legs of said fork-shaped member adapted to engage with the lower ends of the guide members, and a vertically disposed hook shaped member pivoted on said fork-shaped member adapted to coact with the gravity catch and to hold said catch in engagement with the pin on the cross-beam when the grab is supported by the transporter carrlage.

7. In a grab of the type described provided with means connecting the cross-beam carrying the bucket sections and movable sheave block, the combination of means comprising a pin on the cross-beam, a gravity catch comprising a vertically disposed hook shaped member, a horizontally disposed weighted member and a vertically disposed pin carrying member pivoted on the lower sheave block, guide members on the side plates of the upper sheave block, means adapted to coact with the travelling car-- riage of a transporter comprising a forkshaped member adapted to straddle the plates of the upper sheave block and slidably mounted in said guide members enlargements on the ends of the legs of said fork-shaped member adapted to engage with the lower ends oi the guide members, a vertically disposed hook shaped member pivoted on one ofv the legs of saidfork-shapedsmemf. ber adapted tocoact with theY pinA carrying member of the gravity. catch and; toY hold thehoclr-shaped member otthe gravity catchy in engagementt with the pin on; the cross-l beam when the grab is supported bythe transporter i carriage,y andv spring cont-rolled means on the movable sheave block adaptedto;coact witlrthe weighted membenof the.

gravity catch to control the position of said gravity catch.

8. In a grab of the single chain type the combination with means for maintainingthe normal balance of the operative parts of the grab, comprising two vertically disposed telescopic devices arranged one on each side of the sheave blocks, of means connecting the cross-beam carrying the bucket sections and movable sheave block, comprising a p-in on the cross-beam7 a gravity catch pivoted on the lower sheave block, guide members on the side plates of the upper sheave block, means slidably mounted in said guide members adapted to coact with the travelling carriage of a transporter, a vertically disposed hool shaped member pivoted on said means adapted to coact with the gravity catch and to hold said catch in engagement with the pin on the cross-beam when the grab is supported by the transporter carriage, and spring controlled means on the movable sheave block adapted to coact with and control the position of said gravity catch.

9. In a grab of the single chain-type the combination with means for maintaining the normal balance of the operative parts of the grab, comprising two vertically disposed telescopic devices arranged one on each side of the sheave blocks of means connecting the cross-beam carrying the bucket sections and movable sheave block, comprising a pin on the cross-beam, a gravity catch comprising a vertically disposed hook-shaped member, a horizontally disposed weighted member and a vertically disposed pin carrying member pivoted on the lower sheave block, guide members on the side plates of the upper sheave block, means adapted to coact with the travelling carriage of a transporter comprising a fork-shaped member adapted to straddle the plates of the upper sheave block and slidably mounted in said guide members, enlargements on the lower ends of the legs of said fork-shaped member adapted toengage with the lower ends of the guide members, a vertically disposed hook shaped member pivoted on said forkshaped member adapted to coact with the pin carrying member of the gravity catch and to hold the hook-shaped member of the gravity catch in engagement with the pin on the cross-beam when the grab is supported by the transporter carriage, and spring controlled means on the movable sheave block adapted to coact with the weighted member of the gravity catch to control the position of said gravity catch.

l0. In a grab of the single chain type the combination of means for connecting,` the cross-beam Carrying the bucket sections and movable slieave block comprising a pin ou 4lieoross-beam, a gravity eatoh pivoted on the lower slieave block, a pin carried by said gravity catch, guide members on the side plates of the upper sheave block, means slidably mounted in said guide members adapted to eoact with the travelling Carriage of a transporter, means pivoted on said slidable means adapted to ooaet with the pin on the gravity Catch and means on the movable slieave block adapted to coaet with and cont-rol the position of said gravity catch.

DUDLEY JAMES BARNARD. 

